Multi-zone low temperature freezer

ABSTRACT

A freezer provides multiple zones of temperature for preserving a frozen product at an ultra-low temperature. At least one first housing provides a first interior space at a first predetermined temperature. A first compressor, condenser and metering device supply a first refrigerant to a first evaporator for lowering the temperature in the first interior space to the first predetermined temperature. At least one second housing is mounted totally within the first interior space and provides a second interior space for defining a second freezing zone at a second predetermined temperature. The second predetermined temperature is lower relative to the first predetermined temperature. A second compressor, condenser and metering device supply a second refrigerant to a second evaporator for freezing the second housing to the second predetermined temperature. The second compressor, condenser and metering device are disposed within the first interior space to the first evaporator.

CLAIM FOR PRIORITY

The present application claims priority of U.S. Provisional PatentApplication No. 60/892,812 filed on Mar. 2, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to providing a freezer for maintaining aproduct at an ultra-low temperature wherein at least one first housingis maintained at a first predetermined temperature and at least onesecond housing disposed within said at least one first housing ismaintained at a second ultra-low predetermined temperature relative tothe first predetermined temperature of the at least one first housing.

2. Description of Background Art

In the freezing industry, a product can be preserved for a very longtime if the product is stored at an ultra-low temperature in the rangeof approximately −40 to −70 degrees Fahrenheit, −40 to −56.7 Celsius.The colder you store the product the longer the product can bepreserved.

Heretofore, to obtain such an ultra-low temperature for storing aproduct, such as a food product, medical samples or other substancesthat are desired to be stored, it was necessary to construct a specialfreezing unit with a cascaded or multiple stage compressor, condenserand evaporation mechanism designed to achieve the desired ultra-lowtemperature. To construct such a special freezing unit is very expensiveand not economically viable for home use or for use in an environmentwherein an ultra-low temperature freezer would only be used on theoccasional basis.

SUMMARY AND OBJECTS OF THE INVENTION

It is an object of an embodiment of the present invention, to provide anultra-low temperature freezer for providing multiple zones oftemperature for achieving the ultra-low temperature. At least one firsthousing provides a first interior space for defining a first zone thatis maintained at a first predetermined temperature. A first compressoris operatively connected to a first condenser and a first meteringdevice for supplying a first refrigerant to a first evaporator disposedwithin said first interior space for cooling the first interior space tothe first predetermined temperature. At least one second housing ismounted totally within the first interior space. The at least one secondhousing provides a second interior space for defining a second freezingzone at a second predetermined temperature. The second predeterminedtemperature is lower relative to the first predetermined temperature. Asecond compressor is operatively connected to a second condenser and asecond metering device for supplying a second refrigerant to a secondevaporator disposed within the at least one second housing for freezingthe at least one second housing to the second predetermined temperature.The second compressor, the second condenser and the second meteringdevice are disposed within the first interior space and are exposed tothe first evaporator. The first predetermined temperature within thefirst interior space provides a working environmental temperaturerelative to the second predetermined temperature that is the ultra-lowtemperature that is not suitable as a working environment.

In an embodiment of the present invention, the freezer disposed withinthe at least one second housing is a freezer that is completely disposedwithin the first interior space. The freezer is operated with the secondcompressor, the second condenser and the second metering device beingexposed to the first zone wherein the freezer is enabled to reduce thetemperature within the second freezing zone to be the ultra-lowtemperature relative to the first predetermined temperature within thefirst zone.

In an embodiment of the present invention, the first predeterminedtemperature is in a range of approximately −20 to +40 degreesFahrenheit, −28.9 to +4.4 Celsius and the second predeterminedtemperature in a range of approximately −40 to −70 degrees Fahrenheit,−40 to −56.7 Celsius.

In an embodiment of the present invention, the at least one firsthousing is a walk-in housing and the at least one second housing isdisposed within the walk-in housing to enable a working environmentaltemperature within the at least one first housing while maintaining theat least one second housing at the ultra-low temperature.

In an embodiment of the present invention, a number of second housingsare disposed within the first housing wherein an individual can work inthe relatively warmer environment of the first housing.

In an embodiment of the present invention, a at least one first housingis a walk-in housing that is maintained at a low temperature and the atleast one second housing is disposed within the walk-in housing and ismaintained at an ultra-low temperature.

In an embodiment of the present invention, a first thermostat forregulating the first predetermined temperature is disposed within the atleast one first housing wherein the first thermostat regulates thetemperature to be in a range of approximately −20 to +40 degreesFahrenheit, −28.9 to +4.4 Celsius.

In an embodiment of the present invention, a second thermostat forregulating the second predetermined temperature is disposed within theat least one second housing wherein the second thermostat regulates thetemperature to be in a range of approximately −40 to −70 degreesFahrenheit, −40 to −56.7 Celsius.

In an embodiment of the present invention, an atmosphere within thefirst interior space, that is at a first predetermined temperature, isthe medium for cascading the second predetermined temperature within thesecond interior space to be an ultra-low freezing temperature.

In an embodiment of the present invention, a freezer is provided withtwo zones of temperature for preserving a frozen product at an ultra-lowtemperature. At least one first housing provides a first interior spacefor defining a first refrigerated zone at a first predeterminedtemperature. A first compressor is operatively connected to a firstcondenser and a first metering device for supplying a first refrigerantto a first evaporator disposed within the first interior space forcooling the first interior space to the first predetermined temperature.At least one second housing is mounted totally within the first interiorspace. The at least one second housing provides a second interior spacefor defining a second freezing zone at a second predeterminedtemperature, the second predetermined temperature is lower relative tothe first predetermined temperature. A second compressor is operativelyconnected to a second condenser and a second metering device forsupplying a second refrigerant to a second evaporator disposed withinthe second housing for freezing the second housing to the secondpredetermined temperature. The second compressor, the second condenserand the second metering device are disposed within the first interiorspace and are exposed to the first evaporator.

In an embodiment of the present invention, the at least one secondhousing is a freezer that is completely disposed within the firstinterior space, the freezer is operated with the second compressor, thesecond condenser and the second metering device being exposed to thefirst zone wherein the freezer reduces the temperature within the secondfreezing zone to be the ultra-low temperature relative to the firstpredetermined temperature within said first zone.

In an embodiment of the present invention, individuals may work withinthe at least one first housing which may be a larger walk-in coolerenvironment at approximately −20 to +40 degrees Fahrenheit, −28.9 to+4.4 Celsius while a frozen product such as food, medical samples oranother desirable substances may be stored at an ultra-low temperature,as low as approximately −40 to −70 degrees Fahrenheit, −40 to −56.7Celsius by utilization of a freezer to freeze the product for extendedperiods of time. By utilizing a freezer unit within a cold temperatureenvironment of approximately −20 to +40 Fahrenheit, −28.9 to +4.4Celsius, the normal or standard freezer unit can achieve an ultra-lowtemperature of as low as −40 to −70 degrees Fahrenheit, −40 to −56.7degrees Celsius in order to preserve any desired product for an extendedperiod of time, i.e. a decade or more, within a relatively comfortableworking exterior environment of approximately −20 to +40 Fahrenheit,−28.9 to +4.4 Celsius.

In another embodiment of the present invention, multiple zones oftemperature may be utilized. At least one first housing may bemaintained at a first predetermined temperature with at least one secondhousing maintained at a second predetermined temperature and beingdisposed within the at least one first housing. At least one thirdhousing may be maintained at a third predetermined temperature with theat least one third housing being disposed within the at least one secondhousing. The at least one second housing is operated with the secondcompressor, the second condenser and the second metering device beingexposed to the first zone wherein the second housing reduces thetemperature within the second freezing zone to be a low temperaturerelative to the first predetermined temperature within the first zone.The at least one third housing is operated with a third compressor, athird condenser and a third metering device being exposed to the secondfreezing zone wherein the at least one third housing reduces thetemperature within the third freezing zone to be the ultra-lowtemperature relative to the second predetermined temperature within thesecond freezing zone.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 is perspective view illustrating a first housing for positioninga plurality of freezer units within said first housing that forms aworking environment for an individual to gain access to a product thatis frozen at an ultra-low temperature within said freezer units;

FIG. 2 is a perspective view of a first housing with a second housingdisposed within said first housing wherein the second housing maintainsa frozen product at an ultra-low temperature;

FIG. 3 is a schematic view of a compressor, condensor and meteringdevice of the second housing that is positioned within the evaporator ofthe first housing; and

FIG. 4 is a perspective view of a first housing, a second housing and athird housing with the third housing being disposed within the secondhousing and the second housing being disposed within the first housing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in FIG. 1, a low temperature enclosure 10 provides twozones of temperature for preserving a product at a low and ultra-lowtemperature. At least one first housing 11 is provides a first interiorspace 12 for defining a first zone that is maintained at a firstpredetermined temperature. The at least one first housing 11 includes adoor 16 for permitting an individual to gain ingress and egress to thefirst interior space 12. A first compressor 22 is operatively connectedto a first condenser 24 and a first metering device 26 for supplying afirst refrigerant to a first evaporator 28 disposed within said firstinterior space 12 for cooling the first interior space 12 to the firstpredetermined temperature. The following example illustrates threehousing within the low temperature enclosure 10. It is understood thatany number of housings may be positioned within the low temperatureenclosure 10. The present invention is not limited to positioning onlythree housings within the low temperature enclosure 10.

At least one second housing 31 is mounted totally within said firstinterior space 12. The at least one second housing 31 provides a secondinterior space for defining a second freezing zone at a secondpredetermined temperature. The second predetermined temperature is lowerrelative to the first predetermined temperature.

A second compressor 32 is operatively connected to a second condenser 34and a second metering device 36 for supplying a second refrigerant to asecond evaporator 38 disposed within the at least one second housing 31for freezing the at least one second housing 31 to the secondpredetermined temperature. The second compressor 32, the secondcondenser 34 and said second metering device 36 are disposed within thefirst interior space 12 and are exposed to the first evaporator 28.

At least one third housing 41 is mounted totally within said firstinterior space 12. The at least one third housing 41 provides a thirdinterior space for defining a third freezing zone at a predeterminedtemperature. The predetermined temperature is lower relative to thefirst predetermined temperature.

A third compressor 42 is operatively connected to a third condenser 44and a third metering device 46 for supplying a third refrigerant to athird evaporator 48 disposed within the at least one third housing 41for freezing the at least one third housing 41 to the predeterminedtemperature. The third compressor 42, the third condenser 44 and saidthird metering device 46 are disposed within the first interior space 12and are exposed to the first evaporator 28.

At least one fourth housing 51 is mounted totally within said firstinterior space 12. The at least one fourth housing 51 provides a fourthinterior space for defining a fourth freezing zone at a predeterminedtemperature. The predetermined temperature is lower relative to thefirst predetermined temperature.

A fourth compressor 52 is operatively connected to a fourth condenser 54and a fourth metering device 56 for supplying a fourth refrigerant to afourth evaporator 58 disposed within the at least one fourth housing 51for freezing the at least one fourth housing 51 to the predeterminedtemperature. The fourth compressor 52, the fourth condenser 54 and saidfourth metering device 56 are disposed within the first interior space12 and are exposed to the first evaporator 28.

The first predetermined temperature within the first interior space 12provides a working environmental temperature so that an individual mayenter the first interior space 12 through the door 16 to work. Theworking environmental temperature is at a higher temperature relative tothe predetermined temperature within the second, third and fourthhousings 31, 41 and 51 which are all at the ultra-low temperature thatis not suitable as a working environment.

With respect to the housing 10, the at least one second, third andfourth housings 31, 41 and 51 may be freezers that are completelydisposed within the first interior space 14. The freezers are operatedwith the compressors, the condensers and the metering devices that areexposed to the first zone within the first interior space 12 wherein thefreezers are enabled to reduce the temperature within the freezing zoneswithin the at least one second, third and fourth housings 31, 41 and 51to be the ultra-low temperature relative to said first predeterminedtemperature within the first zone.

The housing 10 may include a first predetermined temperature in thefirst interior space 12 that is in a range of approximately −20 to +40degrees Fahrenheit, −28.9 to +4.4 Celsius. The predetermined temperaturein the second, third and fourth housings 31, 41 and 51 may be in a rangeof approximately −40 to −70 degrees Fahrenheit, −40 to −56.7 Celsius.

The housing 10 may include a first thermostat 61 for controlling thefirst compressor 22, the first condenser 24 and first metering device 26to regulate the first predetermined temperature within the first housing12 to be in a range of approximately −20 to +40 degrees Fahrenheit,−28.9 to +4.4 Celsius.

In addition, the at least one second housing 31 may include a thermostat71 for controlling the second compressor 32, the second condenser 34 andsecond metering device 36 to regulate the second predeterminedtemperature within the at least one second housing 31 to be in a rangeof approximately −40 to −70 degrees Fahrenheit, −40 to −56.7 Celsius.

The at least one third housing 31 may include a thermostat 81 forcontrolling the third compressor 32, the third condenser 34 and thirdmetering device 36 to regulate the predetermined temperature within theat least one third housing 31 to be in a range of approximately −40 to−70 degrees Fahrenheit, −40 to −56.7 Celsius.

Further, the at least one fourth housing 31 may include a thermostat 91for controlling the fourth compressor 32, the fourth condenser 34 andfourth metering device 36 to regulate the predetermined temperaturewithin the fourth housing 31 to be in a range of approximately −40 to−70 degrees Fahrenheit, −40 to −56.7 Celsius.

According to the present invention, the housing 10 provides anatmosphere within said first interior space 12 that is at a firstpredetermined temperature that becomes the medium for cascading thepredetermined temperature within the at least one second, third andfourth housings, 31, 41 and 51 to be at the ultra-low freezingtemperature.

As illustrated in FIG. 2, a housing 100 provides two zones oftemperature for storing or preserving a frozen product at an ultra-lowtemperature. At least one first housing 111 provides a first interiorspace 112 for defining a first zone at a first predeterminedtemperature.

A first compressor 122 is operatively connected to a first condenser 124and a first metering device 126 for supplying a first refrigerant to afirst evaporator 128 disposed within said first interior space 112 forcooling said first interior space 112 to the first predeterminedtemperature.

At least one second housing 131 is mounted totally within said firstinterior space 112. The at least one second housing 131 provides asecond interior space 130 for defining a second freezing zone at asecond predetermined temperature. The second predetermined temperatureis lower relative to the first predetermined temperature.

A second compressor 132 is operatively connected to a second condenser134 and a second metering device 136 for supplying a second refrigerantto a second evaporator 138 disposed within the at least one secondhousing 131 for freezing the at least one second housing 131 to thesecond predetermined temperature. The second compressor 132, the secondcondenser 134 and the second metering device 136 are disposed within thefirst interior space 112 and are exposed to the first evaporator 128.

The housing 100 may include at least one second housing 131 that is afreezer that is completely disposed within the first interior space 112.The freezer is operated with the second compressor 132, the secondcondenser 134 and the second metering device 136 being exposed to thefirst zone in the first interior space 112 wherein the freezer reducesthe temperature within the second freezing zone to be the ultra-lowtemperature relative to the first predetermined temperature within saidfirst interior space 112.

In the housing 100 the first predetermined temperature within the firstinterior space 112 may be in a range of approximately −20 to +40 degreesFahrenheit, −28.9 to +4.4 Celsius. In addition, the second predeterminedtemperature in the second interior space 130 may be in a range ofapproximately −40 to −70 degrees Fahrenheit, −40 to −56.7 Celsius.

The housing 100 may include a first thermostat 161 for controlling thefirst compressor 122, the first condenser 124 and first metering device126 to regulate the first predetermined temperature within the at leastone first housing 112 to be in a range of approximately −20 to +40degrees Fahrenheit, −28.9 to +4.4 Celsius.

In addition, the at least one second housing 131 may include athermostat 171 for controlling the second compressor 132, the secondcondenser 134 and second metering device 136 to regulate the secondpredetermined temperature within the at least one second housing 131 tobe in a range of approximately −40 to −70 degrees Fahrenheit, −40 to−56.7 Celsius.

The housing 100 provides an atmosphere within the first interior space112 that is at a first predetermined temperature that becomes the mediumfor cascading the second predetermined temperature within the secondinterior space 130 to be the ultra-low freezing temperature.

As illustrated in FIG. 3, a schematic drawing is set forth wherein afirst interior space 212 is defines a first zone that is maintained at afirst predetermined temperature. A first compressor 222 is operativelyconnected to a first condenser 224 and a first metering device 226 forsupplying a first refrigerant to a first evaporator 228 disposed withinsaid first interior space 212 for cooling the first interior space 212to the first predetermined temperature.

At least one second housing 231 is mounted totally within said firstinterior space 212. The at least one second housing 231 provides asecond interior space for defining a second freezing zone at a secondpredetermined temperature. The second predetermined temperature is lowerrelative to the first predetermined temperature.

A second compressor 232 is operatively connected to a second condenser234 and a second metering device 236 for supplying a second refrigerantto a second evaporator 238 disposed within the at least one secondhousing 231 for freezing the at least one second housing 231 to thesecond predetermined temperature. The second compressor 232, the secondcondenser 234 and said second metering device 236 are disposed withinthe first interior space 212 and are exposed to the first evaporator228. The ultra-low temperature freezer provides an atmosphere within thefirst interior space 212 that is maintained at the first predeterminedtemperature that becomes the medium for cascading the secondpredetermined temperature within the second housing 231 to be theultra-low freezing temperature.

The freezer according to the present invention may be serviced by anyrefrigeration technician. Special knowledge of two-stage systems is notnecessary.

In addition, the present invention reduces the moisture in the lowtemperature enclosures 10, 100, 300 with respect to the ambient airsurrounding the interior housings disposed within the low temperature10, 100, 300. Less moisture in the air will reduce the frequency ofdefrosting needed in the ultra-low temperature freezers and will helpprevent the evaporator coil from icing up due to prolonged or frequentdoor openings.

As illustrated in FIG. 4, in another embodiment of the presentinvention, a freezer 300 with multiple zones of temperature may beutilized. At least one first housing 311 may be maintained at a firstpredetermined temperature with at least one second housing 411 beingmaintained at a second predetermined temperature and being disposedwithin a space 312 of the at least one first housing 311. At least onethird housing 531 may be maintained at a third predetermined temperaturewith the at least one third housing 531 being disposed within a space412 of the second housing 411. A door 316 may be provided to permit anindividual to enter the space 312.

The at least one first housing 311 is operated with a first compressor332, a first condenser 334 and a first metering device 336 with a firstevaporator 328 being mounted within the space 312 for providing a firstpredetermined temperature in the first zone. A first thermostat 361 isoperatively connected to the first compressor 332, the first condenser334 and the first metering device 336 for controlling the temperaturewithin a space 312 the first housing 311 to be at the firstpredetermined temperature.

The at least one second housing 411 is positioned within the space 312and is operated with a second compressor 422, a second condenser 424 anda second metering device 426 being exposed to first evaporator 328 inthe first zone wherein the second housing 411 reduces the temperaturewithin the second freezing zone to be a lower temperature relative tothe first predetermined temperature within the first zone. A secondthermostat 461 is operatively connected to the second compressor 422,the second condenser 424 and the second metering device 426 forcontrolling the temperature within the space 412 in the second housing411 to be at the second predetermined temperature.

The at least one third housing 531 is operated with a third compressor532, a third condenser 534 and a third metering device 536 being exposedto the second evaporator 428 in the second freezing zone wherein the atleast one third housing 531 includes a space 530 with a third evaporator538 being disposed therein for reducing the temperature within the space530 to form a third freezing zone to be at an ultra-low temperaturerelative to the second predetermined temperature within the secondfreezing zone. A third thermostat 571 is operatively connected to thethird compressor 532, the third condenser 534 and the third meteringdevice 536 for controlling the temperature within a space 530 in thethird housing 511 to be at the third predetermined temperature.

The freezer 300 provides an atmosphere within the first interior space312 that is at a first predetermined temperature that becomes the mediumfor cascading the second predetermined temperature within the secondinterior space 412 to be at a second freezing temperature that becomesthe medium for cascading the third temperature within the third interiorspace 530 to be at the third ultra-low temperature. It is to beunderstood that any number of housings may be provided to continue tocascade the temperature from one housing to another to continue to lowerthe temperature within a housing disposed within another housing.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

1. A freezer for providing multiple zones of temperature for preservinga frozen product at an ultra-low temperature comprising: at least onefirst housing providing a first interior space for defining a firstrefrigerated zone at a first predetermined temperature; a firstcompressor being operatively connected to a first condenser and a firstmetering device for supplying a first refrigerant to a first evaporatordisposed within said first interior space for cooling said firstinterior space to said first predetermined temperature; at least onesecond housing mounted totally within said first interior space, said atleast one second housing providing a second interior space for defininga second freezing zone at a second predetermined temperature, saidsecond predetermined temperature being lower relative to said firstpredetermined temperature; and a second compressor being operativelyconnected to a second condenser and a second metering device forsupplying a second refrigerant to a second evaporator disposed withinsaid at least one second housing for freezing said at least one secondhousing to said second predetermined temperature, said secondcompressor, said second condenser and said second metering device beingdisposed within said first interior space and being exposed to saidfirst evaporator; wherein said first predetermined temperature withinsaid first interior space provides a working environmental temperaturerelative to said second predetermined temperature which is an ultra-lowtemperature that is not suitable as a working environment.
 2. Thefreezer according to claim 1, wherein said at least one second housingis a freezer that is completely disposed within said first interiorspace, said freezer being operated with the second compressor, thesecond condenser and the second metering device being exposed to thefirst refrigerated zone wherein the freezer reduces the temperaturewithin said second freezing zone to be the ultra-low temperaturerelative to said first predetermined temperature within said firstrefrigerated zone.
 3. The freezer according to claim 1, wherein saidfirst predetermined temperature is in a range of approximately −20 to+40 degrees Fahrenheit, −28.9 to +4.4 Celsius and the secondpredetermined temperature is in a range of approximately −40 to −70degrees Fahrenheit, −40 to −56.7 Celsius.
 4. The freezer according toclaim 1, wherein said at least one first housing is a walk-in housingand said at least one second housing is disposed within said walk-inhousing to enable a working environmental temperature within said atleast one first housing while maintaining the at least one secondhousing at said ultra-low temperature.
 5. The freezer according to claim4, wherein a plurality of second housings is disposed within said firsthousing.
 6. The freezer according to claim 1, wherein said at least onefirst housing is a freezer and said at least one second housing is afreezer disposed within said at least one first housing.
 7. The freezeraccording to claim 1, and further including a first thermostat forregulating the first predetermined temperature within said at least onefirst housing to be in a range of approximately −20 to +40 degreesFahrenheit, −28.9 to +4.4 Celsius.
 8. The freezer according to claim 7,and further including a second thermostat for regulating the secondpredetermined temperature within said at least one second housing to bein a range of approximately −40 to −70 degrees Fahrenheit, −40 to −56.7Celsius.
 9. The freezer according to claim 1, wherein an atmospherewithin said first interior space that is at the first predeterminedtemperature is the medium for cascading the second predeterminedtemperature within said second interior space to be an ultra-lowfreezing temperature.
 10. A freezer for providing multiple zones oftemperature for preserving a frozen product at an ultra-low temperaturecomprising: at least one first housing providing a first interior spacefor defining a first refrigerated zone at a first predeterminedtemperature; a first compressor being operatively connected to a firstcondenser and a first metering device for supplying a first refrigerantto a first evaporator disposed within said first interior space forcooling said first interior space to said first predeterminedtemperature; at least one second housing mounted totally within saidfirst interior space, said at least one second housing providing asecond interior space for defining a second freezing zone at a secondpredetermined temperature, said second predetermined temperature beinglower relative to said first predetermined temperature; and a secondcompressor being operatively connected to a second condenser and asecond metering device for supplying a second refrigerant to a secondevaporator disposed within said at least one second housing for freezingsaid at least one second housing to said second predeterminedtemperature, said second compressor, said second condenser and saidsecond metering device being disposed within said first interior spaceand being exposed to said first evaporator.
 11. The freezer according toclaim 10, wherein said at least one second housing is a freezer that iscompletely disposed within said first interior space, said freezer beingoperated with the second compressor, the second condenser and the secondmetering device being exposed to the first refrigerated zone wherein thefreezer reduces the temperature within said second freezing zone to bethe ultra-low temperature relative to said first predeterminedtemperature within said first refrigerated zone.
 12. The freezeraccording to claim 10, wherein said first predetermined temperature isin a range of approximately −20 to +40 degrees Fahrenheit, −28.9 to +4.4Celsius and the second predetermined temperature is in a range ofapproximately −40 to −70 degrees Fahrenheit, −40 to −56.7 Celsius. 13.The freezer according to claim 10, wherein said at least one firsthousing is a freezer and said second housing is a freezer disposedwithin said first housing.
 14. The freezer according to claim 10, andfurther including a first thermostat for regulating the firstpredetermined temperature within said at least one first housing to bein a range of approximately −20 to +40 degrees Fahrenheit, −28.9 to +4.4Celsius.
 15. The freezer according to claim 14, and further including asecond thermostat for regulating the second predetermined temperaturewithin said at least one second housing to be in a range ofapproximately −40 to −70 degrees Fahrenheit, −40 to −56.7 Celsius. 16.The freezer according to claim 10, wherein an atmosphere within saidfirst interior space that is at a first predetermined temperature is themedium for cascading the second predetermined temperature within saidsecond interior space to be an ultra-low freezing temperature.
 17. Afreezer for providing multiple zones of temperature for preserving afrozen product at an ultra-low temperature comprising: at least onefirst housing providing a first interior space for defining a firstrefrigerated zone at a first predetermined temperature; a firstcompressor being operatively connected to a first condenser and a firstmetering device for supplying a first refrigerant to a first evaporatordisposed within said first interior space for cooling said firstinterior space to said first predetermined temperature; at least onesecond housing mounted totally within said first interior space, said atleast one second housing providing a second interior space for defininga second freezing zone at a second predetermined temperature, saidsecond predetermined temperature being lower relative to said firstpredetermined temperature; and a second compressor being operativelyconnected to a second condenser and a second metering device forsupplying a second refrigerant to a second evaporator disposed withinsaid at least one second housing for freezing said at least one secondhousing to said second predetermined temperature, said secondcompressor, said second condenser and said second metering device beingdisposed within said first interior space and being exposed to saidfirst evaporator.
 18. The freezer according to claim 17, wherein said atleast one second housing is a freezer that is completely disposed withinsaid first interior space, said freezer being operated with the secondcompressor, the second condenser and the second metering device beingexposed to the first refrigerated zone wherein the freezer reduces thetemperature within said second freezing zone to be the ultra-lowtemperature relative to said first predetermined temperature within saidfirst zone.
 19. The freezer according to claim 17, wherein said firstpredetermined temperature is in a range of approximately −20 to +40degrees Fahrenheit, −28.9 to +4.4 Celsius and the second predeterminedtemperature is in a range of approximately −40 to −70 degreesFahrenheit, −40 to −56.7 Celsius.
 20. The freezer according to claim 17,wherein a plurality of second housings is disposed within said firsthousing.
 21. The freezer according to claim 17, wherein said at leastone first housing is a freezer and said at least one second housing is afreezer disposed within said first housing.
 22. The freezer according toclaim 17, and further including a first thermostat for regulating thefirst predetermined temperature within said at least one first housingto be in a range of approximately −20 to +40 degrees Fahrenheit, −28.9to +4.4 Celsius.
 23. The freezer according to claim 22, and furtherincluding a second thermostat for regulating the second predeterminedtemperature within said at least one second housing to be in a range ofapproximately −40 to −70 degrees Fahrenheit, −40 to −56.7 Celsius. 24.The freezer according to claim 17, wherein an atmosphere within saidfirst interior space that is at a first predetermined temperature is themedium for cascading the second predetermined temperature within saidsecond interior space to be an ultra-low freezing temperature.